There are many medical procedures which require the performance of one or more anastomoses in which a conduit such as a vessel, duct, graft or other tubular structure must be joined to another vessel, duct, or other hollow structure such as an organ to establish continuity between these structures. One of the more prevalent needs for improving anastomosis techniques lies with the treatment of coronary artery disease, where a stenosis of one or more coronary arteries prevents or seriously interferes with a normal blood supply to the heart tissue. In such situations, a total or partial blockage of a coronary artery is often treated by bypassing the obstruction in a heart bypass procedure, such as a coronary artery bypass graft (CABG) procedure, in which a graft is fluidly connected to the blood supply on opposite sides of the site of the stenosis to provide an alternate route for the blood to take on route to the heart.
The graft may be natural conduit, artificial conduit, or a combination of natural and artificial conduits. Typically, a natural conduit in the form of an autograft is used, wherein a saphenous vein is harvested from the leg of the patient or the internal mammary artery is rerouted to be anastomosed downstream of the site of the stenosis.
Conventional CABG procedures are currently performed while the beating of the heart has been stopped, with the circulation and oxygenation of the patient's blood being performed by a heart and lung bypass machine. During this procedure, the aorta of the patient is cross-clamped. Recently, it has been found that the clamping of the aorta introduces a risk of dislodging plaque that may have accumulated on the internal wall of the aorta in the vicinity of the clamping. Dislodgment of plaque can cause emboli in various locations in the patient's body, cutting off the blood supply downstream of the locus of the embolus, which can cause a stroke or other serious medical complications. Further, the heart-lung bypass machine can cause mechanical damage to the blood cells which furthers the risk of medical complications, due to potential clot formation.
Recently there has been an increase in the performance of beating heart CABG procedures, in which the bypass of one or more stenoses is performed while the patient's heart continues to beat, with the circulation and oxygenation of the patient's blood being performed naturally by the heart and lungs of the patient, and during which the aorta is not clamped. While beating heart procedures reduce the associated risks of stroke and other post-operative complications associated with the clamping of the aorta and the use of the heart-lung bypass machine, they also increase the difficulty in performing what were already difficult and delicate anastomosis procedures that must be performed to connect the bypass graft or grafts during the CABG procedure.
The most conventional techniques for making anastomoses involves manually suturing the two tubular conduits together (e.g., manually suturing the graft to the target vessel) around an opening between them. Manual suturing is difficult, time-consuming and requires a great deal of skill and manual dexterity on the part of the surgeon performing the anastomosis. Because of the high level of skill, dexterity and patience required, the results of manual suturing vary considerably from one anastomosis to the next, and from one surgeon to the next. The difficulties presented in performing anastomoses by manual suturing are only magnified when they are done during a beating heart CABG procedure as the beating of the heart introduces perturbations that make it even more difficult to throw the sutures in a reliable and consistent manner.
Thus, there is a need for sutureless anastomosis devices, tools and techniques that offer a reliable alternative to suturing techniques, and which are relatively easier to implement while giving consistent results. It would further be desirable to provide such devices, tools and techniques that would facilitate the performance of higher quality anastomoses than those currently made and with less time required to make the anastomoses.
With continued interest and development toward CABG procedures which are even less invasive than the current techniques for beating heart CABG procedures, it will further be desirable to provide anastomosis techniques which can be performed endoscopically, with the surgeon working outside of the patient.